package net.zoneland.zrdp.common.utils;

import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 线程相关工具类.
 *
 * @author zonevue
 */
public class Threads
{
    private static final Logger LOGGER = LoggerFactory.getLogger(Threads.class);

    private Threads() {
        throw new IllegalStateException("Utility class");
    }
    /**
     * sleep等待,单位为毫秒
     */
    public static void sleep(final long milliseconds) {
        try {
            Thread.sleep(milliseconds);
        } catch (final InterruptedException e) {
            LOGGER.error("线程sleep出错:{}", milliseconds, e);
            Thread.currentThread().interrupt();
        }
    }

    /**
     * 停止线程池
     * 先使用shutdown, 停止接收新任务并尝试完成所有已存在任务.
     * 如果超时, 则调用shutdownNow, 取消在workQueue中Pending的任务,并中断所有阻塞函数.
     * 如果仍然超時，則強制退出.
     * 另对在shutdown时线程本身被调用中断做了处理.
     */
    public static void shutdownAndAwaitTermination(final ExecutorService pool)
    {
        if (pool != null && !pool.isShutdown()) {
            pool.shutdown();
            try {
                if (!pool.awaitTermination(120, TimeUnit.SECONDS)) {
                    pool.shutdownNow();
                    if (!pool.awaitTermination(120, TimeUnit.SECONDS)) {
                        LOGGER.info("Pool did not terminate");
                    }
                }
            } catch (final InterruptedException ie) {
                LOGGER.error("线程池停止出错", ie);
                pool.shutdownNow();
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * 打印线程异常信息
     */
    public static void printException(final Runnable r, final Throwable t) {
        if (t == null && r instanceof Future<?>) {
            try {
                Future<?> future = (Future<?>) r;
                if (future.isDone()) {
                    future.get();
                }
            } catch (final CancellationException | ExecutionException ce) {
                LOGGER.error("future.get err", ce);
            } catch (final InterruptedException ie) {
                LOGGER.error("future.get err", ie);
                Thread.currentThread().interrupt();
            }
        }
        if (t != null) {
            LOGGER.error(t.getMessage(), t);
        }
    }
}
